用遗传算法反演一维声波介质

局部线性化的反演方法不仅在初始模型远离真值时收敛速度慢,而且往往易陷入局部极大值中,而遗传算法(GA)便能解决这一问题,它是一种全局搜索法。虽然它同模拟退火法一样利用转移概率进行搜索,但其收敛速度一般比模拟退火法快。本文引进了多个目标函数进行综合评价和灾变过程,用单道地震道对一维声波介质的速度和密度同时进行了反演,并反演了加噪地震道和含薄层介质模型,取得了满意的效果。     

再谈测距仪加、乘常数的检验

以理论和数据再次阐明测距仪加、乘常数误差的概念和检定原理,指出了国家测距仪检定规程JJG703-2003的不足。     

Optimum seismic zoning for multiple types of structures

We consider zoning for the design criterion that minimizes the expected present value of the total cost, including the initial cost as well as losses due to damage and failure. The problem consists of the following: given the number of zones, their boundaries and design coefficients must be such that they minimize the expected present value of all structures built in the region. We will refer to solutions in one or more dimensions, depending on the number of the types of structures built in the region to be zoned. Two methods are proposed to solve the problems. The first method is based on the different combinations performed in order to attain optimum zoning. The second method uses an analogy to the evolution of biological systems. The work ends by applying the methods developed to a region of known seismicity. Copyright © 2003 John Wiley & Sons, Ltd.     

接收函数反演上地幔速度结构和间断面的剥壳遗传算法

探讨了使用台站接收函数反演得到上地幔速度结构和间断面深度的一种方法——剥壳遗传算法. 由地表至深部分成几个深度段，逐段反演速度结构，并在接收函数曲线上剥离浅处间断面的多次反射震相和反射转换震相对深部间断面的一次透射转换相的影响. 在每一深度段使用浮点编码、算术杂交和非均匀变异的遗传反演方法；在10次独立反演后，依据适应度选出50个优秀模型，对其加权平均得到该段的最终速度结构. 所形成的方法和程序，用iasp’91模型进行数值检验之后，又反演了海拉尔台的观测接收函数，给出台下深至700km的速度结构和主要间断面埋藏深度及速度跃变量.     

水环境模型参数识别的一种新方法

通过在格雷码遗传算法进化过程中加入单纯形搜索算子,并利用格雷码遗传算法和单纯形法所得到的优秀个体群,作为变量新的变化范围,逐步缩小搜索空间,自动向最优解收缩,提出了水环境模型参数识别的一种新方法——格雷码混合加速遗传算法(GCHAGA),给出了实施该算法的详细步骤。对GCHAGA的收敛性和全局优化性进行了理论和实例分析,并在确定河流横向扩散系数等参数识别问题中,GCHAGA得到了精度较高的全局最优解。与格雷码遗传算法(GCGA)和常规优化方法相比,GCHAGA具有精度高、速度快和适用性强等特点,是一种既可以较大概率搜索全局最优解,又能进行局部细致搜索的较好的非线性优化方法,可广泛应用于各种水环境优化问题中。     

基于多目标遗传算法的土地利用空间结构优化配置

针对如何将土地利用数量结构落实到具体的地域空间，以实现土地资源的优化配置的土地利用总体规划编制难点，以及常规的叠加法等土地利用配置方法难以根据土地适宜性评价结果，有效地将土地利用数量结构匹配到具体的土地单元问题，该文利用遗传算法的内在并行机制及其全局优化的特性，提出了基于多目标遗传算法的土地利用空间结构优化配置方法。实例分析表明，该方法具有客观性强、灵活性高、操作简便等优点。     

Genetic Mechanism of Mineral Inclusions in Zircons from the Khondalite Series, Southeastern Inner Mongolia

The early Precambrian khondalite series is widely distributed in the Jining-Zhuozi-Fengzhen-Liangcheng area, southeastern Inner Mongolia. The khondalite series mainly consists of sillimanite garnet potash feldspar (or two-feldspar) gneiss and garnet biotite plagioclase gneiss. These gneissic rocks have commonly experienced granulite-facies metamorphism. In zircons separated from sillimanite garnet potash feldspar gneisses, many mineral inclusions, including Sil, Grt, Ky, Kfs, Qtz and Ap, have been identified by the Laser Raman spectroscopy. Generally, prograde metamorphic mineral inclusion assemblages such as Ky + Kfs + Qtz + Ap and Ky + Grt + Kfs + Qtz are preserved in the core of zircon, while peak granulite-facies metamorphic minerals including Sil + Grt + Kfs + Qtz and Sil + Grt + Kfs + Qtz + Ap are identified in the mantle and rim of the same zircon. However, in some zircons are only preserved the peak metamorphic minerals such as Sil + Grt + Kfs + Qtz and Sil + Grt + Kfs + Qtz + Ap from core to ri     

Genetic Modeling of GIS-Based Cell Clusters and Its Application in Mineral Resources Prediction

This paper presents a synthetic analysis method for multi-sourced geological data from geo-graphic information system (GIS). In the previous practices of mineral resources prediction, a usually adopted methodology has been statistical analysis of cells delimitated based on thoughts of random sam-pling. That might lead to insufficient utilization of local spatial information, for a cell is treated as a point without internal structure. We now take “cell dusters“, L e. , spatial associations of cells, as basic units of statistics, thus the spatial configuration information of geological variables is easier to be detected and utilized, and the accuracy and reliability of prediction are improved. We build a linear multi-discriminating model for the dusters via genetic algorithm. Both the right-judgment rates and the in-class vs. betweewclass distance ratios are considered to form the evolutional adaptive values of the population. An application of the method in gold mineral resoerces prediction in east Xinjiang, China is presented.     

Multidimensional scaling technique for analysis of magnetic storms at Indian observatories

Multidimensional scaling is a powerful technique for analysis of data. The latitudinal dependence of geomagnetic field variation in horizontal component (H) during magnetic storms is analysed in this paper by employing this technique.     

琼西莺歌海盆地断裂系统的成因机制

通过对莺歌海盆地构造变形背景和变形基本特征的分析,详细地研究了盆地断裂系统的特征及其分布规律,并结合区域构造演化,对断裂的成因机制进行了探讨。认为北西向断裂控制了盆地的总体构造格局,尤其是强烈的右旋扭动形成南北向雁行式的张裂隙,诱导了泥-流体底辟构造的发生;泥-流体底辟活动进一步形成局部的应力场,开启新的断裂和破碎带,同时,形成与超压流体的活动相关的流体压裂。